实在找不到以前的讨论所以拿出来开贴问了,大家帮我看看。大雨天跪地劈叉磕头谢谢大家!
给出的答案是D,但是我觉得应该是C。总共的ride次数是C1-3C1-3C1-3=3^3=27,每次ride不同的车总共的次数是1,2,3这3辆车的全排列P1-3=6,所以概率是6/27=2/9。
Q2: A certain roller coaster has 3 cars, and a passenger is equally likely to ride in any 1 of the 3 cars each time that passenger rides the roller coaster. If a certain passenger is to ride the roller coaster 3 times, what is the probability that the passenger will ride in each of the 3 cars?
A. 0 B. 1/9 C. 2/9 D. 1/3 E. 1 |